Synonyms of preconditions

1 Syllable
terms, need, strings, must, rule, catch
2 Syllables
demand, kicker
3 Syllables
exception, provision, proviso, exemption, article, essential, codicil
4 Syllables
stipulation, postulate, necessity, contingency, requirement, arrangement, requisite, reservation
5 Syllables
modification, qualification, prerequisite